学习java的第三十一天
- 作业：
- Employee 类
- Book 类
- Product 类
- Nanny 类
- HomeMain 测试类
作业：
- 使用TreeSet添加员工对象，并按照ID倒序排列。
- 使用LinkedHashSet添加10个书籍对象，并循环输出观察顺序
- 掌握TreeSet、LinkedHashSet与HashSet的异同
- 使用HashTable和ConcurrentHashMap添加10个产品对象，并重写hashCode和equals方法，比较记忆他们余HashMap的异同。
- 使用LinkedHashMap添加10个保姆对象，并分别观察使用accessOrder和不使用accessOrder的区别，并掌握这些区别。
Employee 类
package com.qf.entity;
public class Employee implements Comparable<Object> {
private int id;
private String name;
private String sex;
private int age;
private String dept;
public Employee() {
super();
}
public Employee(int id, String name, String sex, int age, String dept) {
super();
this.id = id;
this.name = name;
this.sex = sex;
this.age = age;
this.dept = dept;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getDept() {
return dept;
}
public void setDept(String dept) {
this.dept = dept;
}
@Override
public String toString() {
return "Employee [id=" + id + ", name=" + name + ", sex=" + sex + ", age=" + age + ", dept=" + dept + "]";
}
@Override
public int compareTo(Object o) {
if(o instanceof Employee){
Employee e = (Employee) o;
if(e.id > this.id){
return 1;
}else if (e.id < this.id) {
return -1;
}
}
return 0;
}
}
Book 类
package com.qf.entity;
public class Book {
private int id;
private String name;
private String type;
public Book() {
super();
}
public Book(int id, String name, String type) {
super();
this.id = id;
this.name = name;
this.type = type;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
@Override
public String toString() {
return "Book [id=" + id + ", name=" + name + ", type=" + type + "]";
}
}
Product 类
package com.qf.entity;
public class Product {
private int id;
private String name;
private String type;
public Product() {
super();
}
public Product(int id, String name, String type) {
super();
this.id = id;
this.name = name;
this.type = type;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + id;
result = prime * result + ((name == null) ? 0 : name.hashCode());
result = prime * result + ((type == null) ? 0 : type.hashCode());
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
Product other = (Product) obj;
if (id != other.id)
return false;
if (name == null) {
if (other.name != null)
return false;
} else if (!name.equals(other.name))
return false;
if (type == null) {
if (other.type != null)
return false;
} else if (!type.equals(other.type))
return false;
return true;
}
@Override
public String toString() {
return "Product [id=" + id + ", name=" + name + ", type=" + type + "]";
}
}
Nanny 类
package com.qf.entity;
public class Nanny {
private int id;
private String name;
private String type;
public Nanny() {
super();
}
public Nanny(int id, String name, String type) {
super();
this.id = id;
this.name = name;
this.type = type;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
@Override
public String toString() {
return "Nanny [id=" + id + ", name=" + name + ", type=" + type + "]";
}
}
HomeMain 测试类
package com.qf.test;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.LinkedHashSet;
import java.util.TreeSet;
import java.util.concurrent.ConcurrentHashMap;
import com.qf.entity.Book;
import com.qf.entity.Employee;
import com.qf.entity.Nanny;
import com.qf.entity.Product;
public class HomeMain {
public static void main(String[] args) {
System.out.println("1. 使用TreeSet添加员工对象，并按照ID倒序排列");
TreeSet<Employee> treeSet = new TreeSet<>();
Employee e1 = new Employee(1, "张三", "男", 25, "人事部");
Employee e2 = new Employee(2, "张三", "男", 26, "人事部");
Employee e3 = new Employee(3, "张三", "男", 27, "人事部");
Employee e4 = new Employee(4, "张三", "男", 28, "人事部");
Employee e5 = new Employee(5, "张三", "男", 29, "人事部");
treeSet.add(e4);
treeSet.add(e5);
treeSet.add(e1);
treeSet.add(e3);
treeSet.add(e2);
Iterator<Employee> iterator = treeSet.iterator();
while(iterator.hasNext()){
System.out.println(iterator.next());
}
System.out.println("2. 使用LinkedHashSet添加10个书籍对象，并循环输出观察顺序");
LinkedHashSet<Book> linkedHashSet = new LinkedHashSet<>();
Book b1 = new Book(1, "财运天降", "小说");
Book b2 = new Book(2, "西游记", "小说");
Book b3 = new Book(3, "红楼梦", "小说");
Book b4 = new Book(4, "三国演义", "小说");
Book b5 = new Book(5, "水浒传", "小说");
Book b6 = new Book(6, "数学", "教材");
Book b7 = new Book(7, "语文", "教材");
Book b8 = new Book(8, "英语", "教材");
Book b9 = new Book(9, "物理", "教材");
Book b10 = new Book(10, "生物", "教材");
linkedHashSet.add(b1);
linkedHashSet.add(b2);
linkedHashSet.add(b4);
linkedHashSet.add(b3);
linkedHashSet.add(b5);
linkedHashSet.add(b7);
linkedHashSet.add(b6);
linkedHashSet.add(b8);
linkedHashSet.add(b9);
linkedHashSet.add(b10);
Iterator<Book> iterator2 = linkedHashSet.iterator();
while(iterator2.hasNext()){
System.out.println(iterator2.next());
}
System.out.println("3. 掌握TreeSet、LinkedHashSet与HashSet的异同");
System.out.println("//相同点:元素不能重复,方法大致一样.");
System.out.println("//不同点:HashSet是无序的,可以添加null元素;LinkedHashSet是有序的,可以添加null元素，顺序是根据你添加的顺序;");
System.out.println("TreeSet是有序的,不能添加null元素;,默认顺序是根据你添加的顺序,也可以按照指定方式,在添加元素时就进行排序,需在实体类写compareTo方法,继承Comparable类.");
System.out.println("4. 使用HashTable和ConcurrentHashMap添加10个产品对象，并重写hashCode和equals方法，比较记忆他们余HashMap的异同。");
Hashtable<String, Product> hashtable = new Hashtable<>();
ConcurrentHashMap<String,Product> concurrentHashMap = new ConcurrentHashMap<>();
Product p1 = new Product(1, "苹果", "手机");
Product p2 = new Product(2, "华为", "手机");
Product p3 = new Product(3, "三星", "手机");
Product p4 = new Product(4, "魅族", "手机");
Product p5 = new Product(5, "小米", "手机");
Product p6 = new Product(6, "苹果", "电脑");
Product p7 = new Product(7, "惠普", "电脑");
Product p8= new Product(8, "联想", "电脑");
Product p9 = new Product(9, "华硕", "电脑");
Product p10 = new Product(10, "戴尔", "电脑");
hashtable.put("a", p1);
hashtable.put("b", p2);
hashtable.put("c", p3);
hashtable.put("d", p4);
hashtable.put("e", p5);
hashtable.put("f", p6);
hashtable.put("g", p7);
hashtable.put("h", p8);
hashtable.put("i", p9);
hashtable.put("j", p10);
Iterator<String> iterator3 = hashtable.keySet().iterator();
while(iterator3.hasNext()){
String key1 = iterator3.next();
System.out.println(key1+"==="+hashtable.get(key1));
}
concurrentHashMap.put("a", p1);
concurrentHashMap.put("b", p2);
concurrentHashMap.put("c", p3);
concurrentHashMap.put("d", p4);
concurrentHashMap.put("e", p5);
concurrentHashMap.put("f", p6);
concurrentHashMap.put("g", p7);
concurrentHashMap.put("h", p8);
concurrentHashMap.put("i", p9);
concurrentHashMap.put("j", p10);
Iterator<String> iterator4 = concurrentHashMap.keySet().iterator();
while(iterator4.hasNext()){
String key2 = iterator4.next();
System.out.println(key2+"==="+concurrentHashMap.get(key2));
}
System.out.println("5. 使用LinkedHashMap添加10个保姆对象，并分别观察使用accessOrder和不使用accessOrder的区别，并掌握这些区别。");
LinkedHashMap<String,Nanny> linkedHashMap1 = new LinkedHashMap<>();
LinkedHashMap<String,Nanny> linkedHashMap2 = new LinkedHashMap<>(4,0.75f,true);
Nanny n1 = new Nanny(1, "张阿姨", "做饭");
Nanny n2 = new Nanny(2, "李阿姨", "洗衣服");
Nanny n3 = new Nanny(3, "王阿姨", "拖地");
Nanny n4 = new Nanny(4, "赵阿姨", "带小孩");
Nanny n5 = new Nanny(5, "周阿姨", "暖被窝");
Nanny n6 = new Nanny(6, "郑阿姨", "陪逛街");
Nanny n7 = new Nanny(7, "刘阿姨", "赚钱");
Nanny n8 = new Nanny(8, "孙阿姨", "挡酒");
Nanny n9 = new Nanny(9, "徐阿姨", "司机");
Nanny n10 = new Nanny(10, "郭阿姨", "保镖");
linkedHashMap1.put("a", n1);
linkedHashMap1.put("b", n2);
linkedHashMap1.put("c", n3);
linkedHashMap1.put("d", n4);
linkedHashMap1.put("e", n5);
linkedHashMap1.put("f", n6);
linkedHashMap1.put("g", n7);
linkedHashMap1.put("h", n8);
linkedHashMap1.put("i", n9);
linkedHashMap1.put("j", n10);
linkedHashMap1.get("a");
Iterator<String> iterator5 = linkedHashMap1.keySet().iterator();
while(iterator5.hasNext()){
String key3 = iterator5.next();
System.out.println(key3+"==="+linkedHashMap1.get(key3));
}
linkedHashMap2.put("a", n1);
linkedHashMap2.put("b", n2);
linkedHashMap2.put("c", n3);
linkedHashMap2.put("d", n4);
linkedHashMap2.put("e", n5);
linkedHashMap2.put("f", n6);
linkedHashMap2.put("g", n7);
linkedHashMap2.put("h", n8);
linkedHashMap2.put("i", n9);
linkedHashMap2.put("j", n10);
linkedHashMap2.get("a");
Iterator<String> iterator6 = linkedHashMap2.keySet().iterator();
while(iterator6.hasNext()){
String key4 = iterator6.next();
System.out.println(key4);
}
Iterator<Nanny> iterator7 = linkedHashMap2.values().iterator();
while(iterator7.hasNext()){
System.out.println(iterator7.next());
}
}
}
